Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden, and it does well by disclosing the key behavioral trait: reusing the idempotency key returns the same import and never creates a second Queue message. It leaves some behaviors unspecified (e.g., error handling or what confirmation triggers), but the most important side-effect is clearly explained.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is short and front-loaded, with the core action in the first sentence. It could be slightly tighter because 'mandatory idempotency key' is repeated as 'The idempotency key is mandatory here,' but the overall structure is efficient and readable.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple three-parameter tool with no output schema, the description covers the essential invocation context and the one behavioral nuance that matters for correct use. It does not describe the response format or failure modes, but nothing critical is missing for an agent to call it correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the baseline is 3. The description adds meaningful semantics for idempotency_key beyond the schema's 'Unique confirmation key' by explaining that reuse returns the same import and prevents duplicate Queue messages. It adds nothing new for import_id or organization_id, but their schema descriptions are sufficient.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a clear action ('Confirm an import') and a specific resource with a notable constraint (mandatory idempotency key). It distinguishes this tool from sibling read/preview operations like contact_import_get and contact_import_preview, though it does not name them explicitly.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives clear context: this tool is for confirming an import and requires an idempotency key, with reuse returning the same import. It explains the practical reason for the idempotency requirement (avoiding duplicate imports on retry) but does not explicitly contrast it with alternatives or state when not to use it.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.